Lead‐free double perovskites are unique materials for transport and optoelectronic applications that use clean resources to generate energy. Using first‐principle computations, this study thoroughly investigates the structural, thermoelectric, and optical attributes of A2TlAgF6 (A = Rb, Cs). Tolerance factor and formation energy estimates are used to verify that these materials exist in the cubic phase. Elastic constants with high melting temperature values are ductile when evaluated for mechanical stability using the Born stability criterion. The optical absorption band is adjusted from 2 to 4 eV via band gaps of 1.88 and 1.99 eV, as indicated by band structures. Analysis of optical properties reveals perfect absorption in the visible spectrum, whole polarization, and low optical loss. Furthermore, thermoelectric properties are assessed at 300, 500, and 700 K in the range of −0.5 to 3 eV for chemical potential (μ). The materials exhibit significant improvements in the Figure of Merit scale due to their elevated electrical conductivity, Seebeck coefficient, and extremely low thermal conductivity values.

中文翻译：

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A2TlAgF6 (A = Rb, Cs) 绿色技术应用的光电和热物理特性

无铅双钙钛矿是用于使用清洁资源产生能源的运输和光电应用的独特材料。这项研究利用第一原理计算，彻底研究了 A 的结构、热电和光学属性2抗原F6（A = 铷、铯）。公差因子和形成能估计用于验证这些材料是否以立方相存在。当使用玻恩稳定性标准评估机械稳定性时，具有高熔化温度值的弹性常数具有延展性。如能带结构所示，光学吸收带通过 1.88 和 1.99 eV 的带隙从 2 eV 调整到 4 eV。光学特性分析揭示了可见光谱的完美吸收、全偏振和低光学损耗。此外，在 300、500 和 700 K 下评估热电性能，化学势范围为 -0.5 至 3 eV（μ）。由于其较高的电导率、塞贝克系数和极低的热导率值，这些材料在品质因数方面表现出显着的改进。